FOREZA · Agarwood Education · HowTo · 4 Steps · 4 Results
By FOREZA Master Grader · 2026-06-04 · 8 min read · Agarwood Education
The water-sinking test is the single most reliable way to verify Sinking-grade Kyara at home. It takes 30 seconds, a clear glass, and room-temperature water. This guide explains the physics behind the test, walks you through the four steps, and shows you how to read the four possible results — so you can look at any piece of agarwood and have a defensible opinion about its grade.
TL;DR
- Use a clear glass, room-temperature water, and a fully dry piece.
- Immediate sink = Sinking-grade Kyara. Slow sink = Semi-Sinking. Float = Chips / Slices / Granules grade.
- The test works because authentic Sinking-grade has density > 1 g/cm³ throughout, not just at the surface.
- For a deeper physics explanation, see Why True Kynam Sinks: The Science of Oleoresin Gravity.
Why the Water Test Works
Wood floats in water because its cellular structure is full of air pockets; the average density of dry wood is 0.4–0.8 g/cm³, well below water's 1.0 g/cm³. For wood to sink, the air pockets must be filled or displaced by something denser than water. In authentic Sinking-grade Kyara, those air pockets are filled with oleoresin — a waxy, semi-solid mixture of essential oils and resin acids that has a density of approximately 1.05–1.15 g/cm³.
When the resin saturation is uniform throughout the piece — heartwood and outer layers alike — the total density exceeds 1.0 g/cm³, and the wood sinks. When the resin is concentrated at the surface (e.g. from a chemical soak), the piece may sink at first but is not truly Sinking-grade throughout.
Note
This is why the test is so effective against fraud. You cannot fake true Sinking-grade by soaking the surface in resin or sugar water — the soak does not penetrate uniformly, and a follow-up cut will reveal the undyed core. Authentic Sinking-grade is resin-saturated from the outside all the way to the center.
What You Need
Three things, all of which you probably already have at home.
- A clear glass (250–500 ml is fine). Must be transparent so you can observe the piece from the side as it falls.
- Room-temperature water (20–25 °C). Do not use hot or cold water; temperature can affect surface tension and slightly slow or speed the descent.
- A fully dry piece of agarwood. If the piece has been stored in a humid environment, leave it in a dry place for 48 hours before testing.
> Tip
If you do not have a piece on hand, you can practice the test with a regular wooden bead. The bead will float, which gives you a reference for what "non-sinking" looks like. This makes it easier to read the result with a real piece.
The 4 Steps
Step 1: Inspect the Piece First
Before the test, hold the piece under natural light and look at the surface. Authentic Sinking-grade Kyara should show irregular dark resin veins running through lighter wood, with a slightly waxy feel. If the surface looks uniformly dark, glossy, or sticky, the wood may have been treated with chemical resin or sugar water. See How to Tell if Agarwood Is Real for the full visual guide.
Step 2: Fill the Glass
Fill the clear glass about three-quarters full with room-temperature water. Tap water is fine; you do not need distilled water.
Step 3: Drop the Piece
Hold the piece about 5 cm above the water surface and release it. Do not push it under. Watch the piece from the side as it enters the water and over the next 30 seconds.
Step 4: Read the Result
Match the behavior to one of the four results in the next section. Most authentic Sinking-grade pieces sink in under 1 second; Semi-Sinking takes 5–30 seconds; floating pieces never sink.
The 4 Possible Results
| Behavior | Likely Grade | What to Do |
|---|---|---|
| Result 1: Sinks immediately (within 1 second) | Sinking-grade Kyara. Density > 1 g/cm³. Resin-saturated throughout. | The piece passes the most rigorous single test for Sinking-grade. Verify visually for irregular resin veins and the aroma test for the multi-layered scent. |
| Result 2: Slowly submerges (5–30 seconds, often with a wiggling motion) | Semi-Sinking grade. Resin-rich but with a lower-density core. | A legitimate grade, not a failure. Semi-Sinking is the second-highest grade and is excellent for bracelets and chips. |
| Result 3: Floats | Standard grade (Chips / Slices / Granules). Resin content is light. | Not Sinking-grade, regardless of label. The piece is still authentic agarwood, just at the entry level. Useful for incense and entry use. |
| Result 4: Surface-bobs, never fully sinks | Likely saturated with water already (smuggler's trick) or has an artificial coating. | Dry the piece thoroughly for 48 hours in a ventilated pouch, then retest. If it still bobs, the piece is almost certainly treated. |
Common Mistakes to Avoid
Three things that can produce a misleading result, even on authentic agarwood.
Mistake 1: Testing a Wet or Humid Piece
Wood that has absorbed water from a humid environment will float or bob, even if it is Sinking-grade when fully dry. Always dry-test a piece. If you receive agarwood in humid weather, leave it in a dry place for 48 hours before running the test.
Mistake 2: Using Hot or Cold Water
Water temperature affects surface tension and viscosity. Hot water can produce bubbles on the wood surface that slow the descent. Cold water (below 10 °C) is more viscous and slows the fall. Use room-temperature water (20–25 °C) for the most reliable result.
Mistake 3: Pushing the Piece Under
Some buyers, in their eagerness, push the piece to the bottom of the glass and conclude it is "sinking." That is not a valid test. The piece must be released above the water surface and descend under its own weight.
After the Test: The Aroma Test
The water test is one of three reliable home tests. For a complete picture, follow it with the aroma test: heat the piece gently on an electric agarwood heater (80–120 °C, never direct flame) and observe the multi-layered scent (sweet honey → cooling menthol → deep wood). Fades within minutes = fake. See the full aroma test in How to Tell if Agarwood Is Real.
Single-Origin
Guanzhu Town, Dianbai District, Maoming City, Guangdong, China — the historical "Capital of Chinese Agarwood." Every FOREZA piece is traceable to this origin.
Not Vietnam. Not Indonesia. Not Hainan. 100% authentic Guanzhu agarwood.
Try the Test on a Verified FOREZA Piece
Every product ships with a hand-signed Certificate of Authenticity. If a piece fails any of the three home tests, we refund you in full.
Discover Kyara →Continue Exploring
- How to Tell if Agarwood Is Real (3 tests, 5 scams)
- Why True Kynam Sinks: The Science of Oleoresin Gravity
- Why Your "Kynam" Might Just Be Chemically Induced Agarwood
- How to Spot Fake Agarwood (Education Pillar)
- Certificate of Authenticity
- Frequently Asked Questions
FOREZA Master Grader
Direct from Guanzhu, the Capital of Chinese Agarwood. Every piece we ship is personally inspected and water-tested at our workshop. Reach us at zhangxiaobao217@gmail.com.